Of course, I’m assuming the OP doesn’t actually need his stereo to work during a power outage! :)
Usually when I read about UPS for audio gear users want to recreate something like a PS Audio power plant on the cheap by finding a "line interactive" sine wave output UPS. In those cases I think they should stick to Furman and "normal" voltage regulators. In part due to the AC line noise they generate, in part because from what I’ve read, true sine wave UPS systems tend to have lower reliability than their square wave brethren. Honestly you usually get cleaner power out of the wall.
If you actually need to keep your HT system going to make sure it doesn’t shut off your movie that’s another story.
My work PC, my router/Internet hardware are all on APC UPS units. That’s what I need to keep going even when the power is out. I just got a beer fridge for the gaming PC, I should probably consider putting that on a UPS too.
When the power gets glitchy (and it does!) I trust my Furman protections to shut off the power to my gear until things stabilize. If I want to ignore blackouts I should probably get a generator.